Search results for "fluorescent"
showing 10 items of 863 documents
Diversity and Evolution of the Phenazine Biosynthesis Pathway
2010
ABSTRACT Phenazines are versatile secondary metabolites of bacterial origin that function in biological control of plant pathogens and contribute to the ecological fitness and pathogenicity of the producing strains. In this study, we employed a collection of 94 strains having various geographic, environmental, and clinical origins to study the distribution and evolution of phenazine genes in members of the genera Pseudomonas , Burkholderia , Pectobacterium , Brevibacterium , and Streptomyces . Our results confirmed the diversity of phenazine producers and revealed that most of them appear to be soil-dwelling and/or plant-associated species. Genome analyses and comparisons of phylogenies inf…
Calix[4]arene-functionalized naphthalene and perylene imide dyes.
2002
[reaction: see text] Calix[4]arenes bearing one, two, or four 1,8-naphthyl imide groups at the wide rim and bis-calix[4]arenes connected via perylene-bisimide dye spacers have been synthesized. The low-temperature NMR spectrum of the tetranaphthylimide suggests, in agreement with a crystal structure, a C2-symmetrical pinched cone conformation stabilized via face-to-face pi-pi interactions between opposite naphthylimide groups. UV-vis and fluorescence studies have been carried out for the perylene bis-calix[4]arene dyes.
Paracrine in vivo inhibitory effects of adipose tissue–derived mesenchymal stromal cells in the early stages of the acute inflammatory response
2015
Abstract Background aims Excessive or unresolved inflammation leads to tissue lesions. Adipose tissue–derived mesenchymal stromal cells (AMSCs) have shown protective effects that may be dependent on the modulation of inflammation by secreted factors. Methods We used the zymosan-induced mouse air pouch model at two time points (4 h and 18 h) to evaluate the in vivo effects of AMSCs and their conditioned medium (CM) on key steps of the early inflammatory response. We assessed the effects of AMSCs and CM on leukocyte migration and myeloperoxidase activity. The levels of chemokines, cytokines and eicosanoids in exudates were measured by use of enzyme-linked immunoassay or radio-immunoassay. In …
Direct subphthalocyanine conjugation to bombesin vs. indirect conjugation to its lipidic nanocarrier
2016
International audience; Bombesin (BBN) was covalently bound to graftable subphthalocyanine (SubPc) or to a cholesterol derivative, a component of a liposome that encapsulates non-graftable SubPc. The latter bioconjugation approach was suitable to address the stability of SubPc and was achieved by copper-free click-chemistry on the outer-face of the liposome. Liposomes were purified (FPLC) and then analyzed in size (outer diameter about 60 nm measured by DLS). In vitro binding studies allowed to determine the IC50 13.9 nM for one component of the liposome, cholesterol, conjugated to BBN. Hence, azido- (or alkynyl-) liposomes give fluorophores with no reactive functional group available on th…
Probes for studying cholesterol binding and cell biology.
2011
Cholesterol is a multifunctional lipid in eukaryotic cells. It regulates the physical state of the phospholipid bilayer, is crucially involved in the formation of membrane microdomains, affects the activity of many membrane proteins, and is the precursor for steroid hormones and bile acids. Thus, cholesterol plays a profound role in the physiology and pathophysiology of eukaryotic cells. The cholesterol molecule has achieved evolutionary perfection to fulfill its different functions in membrane organization. Here, we review basic approaches to explore the interaction of cholesterol with proteins, with a particular focus on the high diversity of fluorescent and photoreactive cholesterol prob…
Direct sequencing of human gut virome fractions obtained by flow cytometry
2015
The sequence assembly of the human gut virome encounters several difficulties. A high proportion of human and bacterial matches is detected in purified viral samples. Viral DNA extraction results in a low DNA concentration, which does not reach the minimal limit required for sequencing library preparation. Therefore, the viromes are usually enriched by whole genome amplification, which is, however, prone to the development of chimeras and amplification bias. In addition, as there is a very wide diversity of gut viral species, very extensive sequencing efforts must be made for the assembling of whole viral genomes. We present an approach to improve human gut virome assembly by employing a mo…
Highly Selective Detection of Nerve‐Agent Simulants with BODIPY Dyes
2014
Two chromo-fluorogenic probes, each based on the boron dipyrromethene core, have been developed for the detection of nerve-agent mimics. These chemosensors display both a color change and a significant enhancement of fluorescence in the presence of diethylcyanophosphonate (DCNP) and diisopropylfluorophosphate (DFP). No interference from other organophosphorus compounds or acids has been observed. Two portable chemosensor kits have been developed and tested to demonstrate its practical application in real-time monitoring.
Cytotoxicity of Metal and Semiconductor Nanoparticles Indicated by Cellular Micromotility
2009
In the growing field of nanotechnology, there is an urgent need to sensitively determine the toxicity of nanoparticles since many technical and medical applications are based on controlled exposure to particles, that is, as contrast agents or for drug delivery. Before the in vivo implementation, in vitro cell experiments are required to achieve a detailed knowledge of toxicity and biodegradation as a function of the nanoparticles' physical and chemical properties. In this study, we show that the micromotility of animal cells as monitored by electrical cell-substrate impedance analysis (ECIS) is highly suitable to quantify in vitro cytotoxicity of semiconductor quantum dots and gold nanorods…
Cutting Edge: An IL-17F-CreEYFP Reporter Mouse Allows Fate Mapping of Th17 Cells
2009
Abstract The need for reporter lines able to faithfully track Th17 cells in vivo has become an issue of exceptional importance. To address this, we generated a mouse strain in which Cre recombinase is expressed from the IL-17F promoter. Crossing the IL-17F-Cre allele to a conditional enhanced yellow fluorescent protein (EYFP) reporter mouse yielded the IL-17F-CreEYFP strain, in which IL-17F expression is twinned with EYFP in live IL-17F-expressing cells. Although we demonstrate that IL-17F expression is restricted to CD4+ T cells during experimental autoimmune encephalomyelitis, IL-17F-CreEYFP CD8 T cells robustly expressed IL-17F in response to TGF-β, IL-6, and IL-23. Fate mapping of IL-17…
HSP90 and eNOS partially co-localize and change cellular localization in relation to different ECM components in 2D and 3D cultures of adult rat card…
2007
Background information. Cultivation techniques promoting three-dimensional organization of mammalian cells are of increasing interest, since they confer key functionalities of the native ECM (extracellular matrix) with a power for regenerative medicine applications. Since ECM compliance influences a number of cell functions, Matrigel-based gels have become attractive tools, because of the ease with which their mechanical properties can be controlled. In the present study, we took advantage of the chemical and mechanical tunability of commonly used cell culture substrates, and co-cultures to evaluate, on both two- and three-dimensional cultivated adult rat cardiomyocytes, the impact of ECM c…